First Click: Every backpack should have side access

Two ergonomic oddities persist in our world that make zero sense to me: perfectly circular over-ear headphones and backpacks that only load from the top down. The first should be self-explanatory, as our ears are D-shaped rather than circular, but the second might be a little less obvious. Allow me to elaborate on the matter, using the stellar Everyday Backpack from Peak Design as the role model.
The archetypal backpack is an upright rectangle, spanning the space from the waist of its wearer up